Add HeadlessTabSocket

headless/public/headless_tab_socket.h

Index: headless/public/headless_tab_socket.h
diff --git a/headless/public/headless_tab_socket.h b/headless/public/headless_tab_socket.h
new file mode 100644
index 0000000000000000000000000000000000000000..efc2323759f98231ebc5776371f3df8e9e881b1d
--- /dev/null
+++ b/headless/public/headless_tab_socket.h
@@ -0,0 +1,43 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef HEADLESS_PUBLIC_HEADLESS_TAB_SOCKET_H_
+#define HEADLESS_PUBLIC_HEADLESS_TAB_SOCKET_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "headless/public/headless_export.h"
+
+namespace headless {
+
+// A bidirectional communications channel between C++ and JS.
+class HEADLESS_EXPORT HeadlessTabSocket {
+ public:
+  class HEADLESS_EXPORT Listener {
+   public:
+    Listener() {}
+    virtual ~Listener() {}
+
+    virtual void OnMessageFromTab(const std::string& message) = 0;

[Sami, 2017/04/12 14:18:46]

Maybe add a note here reminding that the message may be potentially sent by
untrusted web content so it should be validated carefully.

[alex clarke (OOO till 29th), 2017/04/12 15:47:46]

Done.

+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(Listener);
+  };
+
+  virtual void SendMessageToTab(const std::string& message) = 0;
+
+  virtual void SetListener(Listener* listener) = 0;
+
+ protected:
+  HeadlessTabSocket() {}
+  virtual ~HeadlessTabSocket() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HeadlessTabSocket);
+};
+
+}  // namespace headless
+
+#endif  // HEADLESS_PUBLIC_HEADLESS_TAB_SOCKET_H_